Halogenated aromatic ethers

Abstract

Suitable as lubricants or dielectric fluids are ethers of the formula ##SPC1##

Wherein X is F or H, at least one of the substituents X being F, n is a whole number at least equal to 1, R and R' being identical or different represent H or Cl.

Description

BACKGROUND OF THE INVENTION

This invention relates to benzhydryl fluoroalkyl ethers. Such compounds are useful, for example, as lubricating and dielectric fluids.

A wide variety of halogenated ethers have been disclosed in U.S. patents, for example U.S. Pat. Nos. 2,831,033, 2,409,274, 3,661,967, 2,564,214 and 2,702,825, as well as in foreign patents, for example French Pat. Nos. 1,463,398 and 1,501,630.

SUMMARY

An object of this invention is to provide novel ethers and a process for preparing same.

Upon further study of the specification and appended claims, further objects and advantages of this invention will become apparent to those skilled in the art.

To attain these objects, there are provided benzhydryl fluoroalkyl ethers of the formula ##SPC2##

Wherein X is F or H, at least one of the substituents X being F, n is a whole number at least equal to 1, R and R' being identical or different represent H or Cl.

Owing to their physical chemical properties: high viscosity and high boiling point, these novel compounds are useful lubricants, hydraulic fluids and dielectric fluids.

The compounds of this invention are obtained by reacting benzhydrol or one of its derivatives which are halogenated on the benzene ring, with a halogenated aliphatic linear primary saturated alcohol.

DETAILED DISCUSSION

The benzhydrol and its derivatives have the formula: ##SPC3##

Wherein R and R' are identical or different and are H or Cl. Suitable compounds include: benzhydrol (diphenylmethanol), parachloro diphenylmethanol and para-dichloro diphenylmethanol. For purposes of simplification, the term "benzhydrol" is used herein to designate the different compounds having the formula as defined hereabove.

Aliphatic saturated linear primary alcohols suitable for preparing the ethers of the present invention are alcohols having the formula:

c_n X₂n+1 CH₂ OH

wherein X is F or H, at least one X being F, and n is a whole number at least equal to 1, and preferably not more than 6 the particularly preferred range for n being 1-4.

In the practice of the invention, the alcohols preferably used are the alcohols either partly or entirely substituted by fluorine on the carbon atoms which do not carry the alcohol function. Among suitable alcohols, fluorinated primary alcohols such as ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol can be cited.

The reaction is performed by heating at about 50°C, a mixture constituted by the halogenated starting alcohol and an acidic dehydration agent. The halogenated starting alcohol is preliminarily dissolved in an aromatic solvent such as benzene, toluene, xylene and the like. The acid dehydration agent is for example concentrated sulfuric acid of hydrochloric acid and is used in a small quantity. Then the benzhydrol preliminarily dissolved in the same solvent as the halogenated alcohol is added to the reaction mixture. The reaction is achieved by heating and refluxing the reaction mixture with stirring for 1 to 7 hours.

According to the present invention, stoichiometric quantities of the fluorinated alcohol and of the benzhydrol can be used but preferably an excess of the fluorinated alcohol is used. Generally the amount of fluorinated alcohol ranges between 110 and 220 percent by weight and preferably 120 and 200% by weight of the molar theoretical quantity.

When the reaction is completed, the reaction mixture is treated with water. After decantation, the organic phase is washed successively with a weakly alkaline solution (for instance sodium bicarbonate) up to a pH of about 7 and finally with water. After decantation and drying (for example with calcium chloride), the aromatic solvent and the unreacted fluorinated alcohol are eliminated according to known techniques such as evaporation under vacuum, and the organic phase is distilled off under vacuum in order to obtain the aralkyl ether. According to the nature of starting reactants, aralkyl ethers yields can vary from 30 to 90 percent by weight based on the used benzhydrol.

Due to their physico-chemical properties: high viscosity and high boiling point, the ethers according to the present invention are useful lubricants, hydraulic fluids and dielectric fluids.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The following preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever. In the following examples, all temperatures are set forth uncorrected in degrees Celsius; unless otherwise indicated, all parts and percentages are by weight.

EXAMPLE 1

In a reaction vessel (500ml) provided with a magnetic stirrer, a condenser and a dropping funnel, 0.5 mole (50g) of trifluoroethanol were introduced and dissolved in 50ml of dry benzene. Then 5ml of concentrated sulfuric acid were introduced: the mixture was stirred and heated by gradually raising the temperature to 50°C. Then, 0.25 mole (46g) of benzhydrol preliminarily dissolved in 70ml of benzene by heating, was slowly added to the reaction mixture. The mixture was stirred and refluxed for 6 hours.

After cooling, water was added to the reaction mixture. The acidic organic phase was neutralized with a sodium bicarbonate solution and washed with distilled water. After decantation and drying with calcium chloride the organic phase was evaporated by a water jet aspirator.

After distillation under vacuum (10mm Hg), there were obtained 50g of an oily yellowish product. An analytical study by vapor phase chromatography revealed that this product contained impurities. After redistillation under a vacuum of 10 mm Hg there were obtained 46g of 1-trifluoro-ethyl benzhydryl ether corresponding to a yield of 70 percent by weight based on the consumed benzhydrol. This ether was an amorphous white product having the following properties:

B.p. : 263°c

m.p. : 25 to 32°C

n_D³0 : 1.5070

N.m.r. analysis showed:

δ .sub.>CH_--O = 5.45 p.p.m. (singlet)

δ _--CH_2--O = 3.5 to 3.9 p.p.m. (quartet)

δ (C₆H₅)₂< = 7.3 p.p.m. (main singlet of multiplet)

The data are consistent with and support the structure of the ether of formula:

(C₆ H₅)₂ --CH--O--CH₂ --CF₃

example 2

example 1 was repeated by using benzhydrol (C₆ H₅)₂ CHOH and various halogenated alcohols. The obtained products are shown in Table 1.

EXAMPLE 3

In a reactor vessel equipped as described in Example 1, 44g (0.3 mole) of 2,2,3,3, tetrafluoropropanol-1 (CF₂ H--CF₂ --CH₂ OH), 50ml of dry benzene and 5ml concentrated sulfuric acid were introduced. The reaction mixture was heated at 50°C, and a hot mixture of 54.6g (0.25 mole) of para-chlorobenzhydrol dissolved in 100ml of dry benzene was introduced. The reaction mixture was stirred at 50°C for 30 minutes; then the mixture was refluxed for 6 hours.

After cooling, the organic phase was neutralized at pH 7 with an alkaline solution, washed with water and dried with calcium chloride. Benzene was evaporated. The obtained oily product was distilled under vacuum, 53 grams of 1,1,2,2, tetrafluoropropyl para-chlorobenzhydryl ether were obtained corresponding to a yield of 63 percent by weight based on the consumed p-chlorobenzhydrol.

The obtained product had the following properties:

B.p. : 321°-322°c (decomposition)

n D²0 : 1.5202

Viscosity at 20°C : 75 centistokes

Viscosity at 37.8°C : 19 centistokes

Viscosity at 98.9°C : 2.5 centistokes

N.m.r. spectra of the 1,1,2,2, tetrafluoropropyl para-chlorobenzhydryl ether confirms its structure ##EQU1## δ (C₆H_5--,C₆H₄Cl_--) = 7.2 p.p.m. (main singlet of multiplet)

δ (>CH_--O_--) = 5.3 p.p.m. (singlet)

δ (_--CH_2--O_--) = 3.5 to 4 p.p.m. (triplet)

δ (HCF_2--CF_2--) = 5.8 p.p.m. (triplet of triplets with a center at 5.8 p.p.m.)

N.m.r. spectrum achieved on F₁9 confirms also this structure.

EXAMPLE 4

By using the mode of operation of Example 3, other ethers were obtained by reacting p-chlorobenzhydrol and 4,4'-dichlorobenzhydrol with various fluorinated alcohols. In Table 2, the results are set forth.

The nuclear magnetic resonance (NMR) spectra of the ethers obtained according to the present invention were achieved by using a 60 M.C. apparatus.

TABLE 1
__________________________________________________________________________
Starting fluorinated
Obtained ether
Physical constants of
NMR spectrum of the obtained ether
Alcohol                 the obtained ether
__________________________________________________________________________
CF3 CF2 CH2 OH
(C6 H5)2 CHOCH2 CF2 CF3
B.P.
: 262°C
δ(C6H5)2
<
:
7.3 p.p.m.
(main singlet of multiplet)
2,2,3,3,3-pentafluoro-
1,1,1,2,2-pentafluoropropyl
M.P.
≡
-55°C
propanol-1  benzhydryl ether         δ(>CH--O)
:
5.4 p.p.m. (singlet)
nD20
: 1.489
Viscosity at 20°C :
δ(--CH2--O
--)
:
3.5 at 4 p.p.m. (triplet)
13.44 centistokes
HCF2 CF2 CH2 OH
(C6 H5)2 CHOCH2 CF2 CF2
B.P.
: 298°C
δ(C6H5)2
<
:
7.2 p.p.m.
(main singlet multiplet)
2,2,3,3-tetrafluoro-
1,1,2,2-tetrafluoropropyl
nD20
: 1.5060
propanol-1  benzhydryl ether         δ(>CH--O--)
:
5.3 p.p.m. (singlet)
d20
: 1.23478
Viscosity at 20°C :
δ--CH2O--)
:
3.4 at 3.9 p.p.m. (triplet)
37.28 centistokes
δ((HCF2--)
:
5.8 p.p.m. (triplet of
triplets with a center at
5.8 p.p.m.)
CF2 H--(CF2)3 --CH2 OH
(C6 H5)2 CH--O--(CH2)(CF2)3
B.P.
: 270°C
δ(C6H5)2
<
:
7.25 p.p.m.
(main singlet of multiplet)
2,2,3,3,4,4,5,5-octa-
CF2 H     nD20
: 1.473
fluoropentanol-1
1,1,2,2,3,3,4,4-octafluo-
Viscosity at 20°C :
δ.sub.>(CH--O--)
:
5.4 p.p.m. (singlet)
ropentyl benzhydryl ether
48.64 centistokes
--CH2--O--)
:
3.7 at 4 p.p.m. (triplet)
δ(--HCF2)
:
5.9 p.p.m. (triplet of
triplets with a center at
5.9 p.p.m.)
__________________________________________________________________________

Table 2
__________________________________________________________________________
Starting
fluorinated
Obtained ether  Physical constants of
NMR spectrum of the obtained ether
alcohol                  the obtained ether
__________________________________________________________________________
CF3 CH2 OH
p-ClC6 H4
B.P.:306°C
δ(C6H5--)
=       7.2 p.p.m. (main
2,2,2-trifluoro-
∠CH--OCH2 CF3
nD20 :1.5211
singlet of a multiplet)
ethanol-1
C6 H5 Viscosity at 20°C:
δ.sub.>(CH--O--)
=       5.3 p.p.m. (singlet)
1,1,1-trifluoroethyl-
20 centistokes
δ--CH2--O.
sub.--) =
3.4 p.p.m. (quartet)
para monochloro-benzhydryl           at 3.8 p.p.m.
ether
CF3 CH2 OH
p-ClC6 H4
M.P.:341-342°C
δ(C6H4Cl).sbsb
.2< 7.2 p.p.m. (main
2,2,2-trifluoro-
∠CH--OCH2 CF3
(decomposition)
ethanol-1
p-ClC6 H4
nD20 :1.5333
δ.sub.>(CH--O--)
=       5.4 p.p.m. (singlet)
1,1,1-trifluoroethyl-
d20:1.35111 δ--CH2--O)
=       3.5 at 3.9 p.p.m.
(quartet)
para-dichloro benzhydryl
Viscosity at 20°C:
ether           52.73 centistokes
CF2 HCF2 CH2 OH
p-ClC6 H4
B.P.:147-155°C/
NMR spectrum confirms the presence
2,2,3,3 tetra-
∠CH--OCH2 CF2 CF2 H
1mm         of radicals : (C6 H4
Cl)>(CHO) and
fluoro-  p-ClC6 H4
(decomposition)
--(HCF2), but the ether is
impure.
propanol-1
1,1,2,2-tetrafluoropropyl-
impure heavy oil
para dichloro benzhydryl
Viscosity at 20°C:
ether           206 centistokes
__________________________________________________________________________

The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

Claims

1. An ether of the formula: ##SPC4##

wherein R" is an alkyl of not more than 6 carbon atoms and has at least 3 fluorine atoms bonded thereto, R and R' being identical or different

2. An ether according to claim 1 wherein R" is an alkyl of not more than 4

9. (C₆ H₅)₂ --CH--O--CH₂ --CF₃ according to claim

10. (C₆ H₅)₂ --CH--O--CH₂ --CF₂ --CF₃

11. (C₆ H₅)₂ --CH--O--CH₂ --CF₂ --CF₂ H

12. (C₆ H₅)₂ --CH--O--CH₂ --(CF₂)₃ --CF₂

13. ##EQU2## according to claim 1.

14. ##EQU3## according to claim 1.

15. ##EQU4## according to claim 1.

16. ##EQU5## according to claim 1.